Collapsible core



Aug. 4, 1931. F. L. JOHNSON COLLAPSIBLE CORE Filed Aug. 5. 1929 2' Sheets-Shet 1 Q I INVENTOR f f Y /f A. dam/Jam.

ATTORNEYJ;

F; L. JOHNSON COLLAP SIBQLE CORE Y Fiied' Aug.

4 Aug. 4, 1931.

'5, 1929' 2 Sheets-Sheet 2 INVENTOR firm/K L. Jam/mam.

Patented Aug. 4, 1931 Y UNITED STATES FRANK L. JOHNSON, or AKRON, OHIO COLLAPSIIBLE CORE Application filed August 5, 1929, Serial No. 383,512.

The present invention relates to the art of building pneumatic tires for automobiles, trucks or the like, and particularly to the construction ofcollapsible cores or forms upon which the said tires are built.

practical core of this type which may be easily and quickly-assembled for the building of the tire thereon, the several sections or segments of the core being accurately positioned and aligned. It is also possible with the improved core shown herein to separate and remove the sections rapidly and efliciently. i r

The invention secures a simple and practical collapsible core,'which may be used in ii the building of the'large tires referred to,

although it is not necessarily limited to that definite use, the principlesof the invention being applicable to all sizes of tire building cores. Neither is the invention limited 'to to use with tire building cores, as distinguished from drums, but may be adapted for use with any collapsible building 'form.

The-drawings herein and the specification illustrate the best known embodiment 3.3 of the inventionand are not-intended as indicating the limits thereof, as changes and modifications may be made in specific embodiments of the invention, Without sacrificing any of the: benefits or advantages 4' thereof. I

In the drawings, Figure l is a planview of the assembled core in the form in which the tire is to be built;

4 Figure 2 is a vertical section on the line 2 2 of Figure 1;-

. Figure 3 is an enlarged view showing the details of the mechanism for clamping the core sections to the central chuck or plate;

' and clamps 18 which maybe fan shaped as Figures 4. and 5 are details of a modification.

The core or form comprises a body which is of the required cross section for the manufacture of the tire therein. As shown, it f is in the form of the usual rounded section, although the profile thereof may be altered or varied. M

The core body is cut or, divided into a plurality of segments. or sections according to the manner in'which the core is to'be disassembled, andaccording to the size or bulkthereof. A satisfactory design for this purpose is shown in Figure 1, wherein, the core is divided into six sections designated by the numeralsjlto 6 inclusive. -The section 1 may be termed the. key section, as it is the first section to be moved in collapsing the core, beingcprovided with sides which converge outwardly so that the section can be removed from the finished tire. The remaining sections may be divided as found necessary or advisable, the lines of division Whichare shown being satisfactory for the purpose.

Located centrally of the/core is the central supporting plate or chuck 10 which is vprovided with the opening 11 therein, by

means of which the core may be mounted on the shaft of the tire, buildingmachine or stand, and by which the core may be rotated.

The outer surface or periphery of the central plate is formed with an annular surface or face 12, which may taper as shown, and each of the core sections is formed in its inner face with a corresponding surface adapted to rest against and register on the surface 12. About the seating surface or register, the supporting plate 1s provided with an undercut angularly shaped rib 14, forming an angular groove in which is receivable the angular web or dovetail 15 on the base or tongue of the core sectionl On the opposite side of the tongue on the core section is formed the angular groove or recess 16. Located around the central supporting plate are the series of radial shown, so that the outer edge of each clamp extends over a considerable surface. As shown, certain of these clamps embrace more than one core section. The outer edge of each clamp is formed with a nose or angular rib 20, which seats in the groove 16. Each clamp is formed with radial slot 21 which-passes over a bolt 22 seated in the core plate. A nut 24 is screwed upon the outer end of the bolt, a washer 25 being located beneath the nut. "A light spring plate 28 is located below the nut and washer and a guiding pin 30 may be set'i'n'each clamp, the pin engaging-amotch 32--ir1 the core plate so that the clamp moves radially when being tightened. The slot and pin are of sufficient length so that the clamps may be moved down into'a'position to clear the core segments, without disassembling the clamps. "It will beseenthatwhen"the core segments'are located'in position and the clamps applied, the sections are drawn wdown against the register "or the central plate, insuring apositionalignment of the core sections about the' central plate. In previous constructions, the cores have been held upon the core shaft by means of expanding chucks, but the present construction provides for the pulling in of the core sections against the central registeror cylindrical surface 12. Asa result aperfectly circularity of the core is obtained. The core sections are formed and securely clamped about the central supportingplate or chuck and the completed core is balanced evenly and will run smoothly upon its'axis. In removing the tire, the clamps are re leased and the collapsible core'with'the tire thereon is removed from the central plate, whereupon the sections can'be removed from the tire.

The key section 1 may be provided with a recess 31- in which a leveror grappling hook may be received for the purpose of pulling out the key sections.

In the form shown in Figures land 5,

each core section may be drawndown upon the-register 30011 the chuck plate by stud boltsor screws 38' which work in the slots 40 on the chuck plate '10.

"It will be apparentthat other means may be devised for drawing down and clamping the core sections in the register'about the chuck plate, but it is believed that the clamps shown and described will serve the purpose to better advantage than other mechanisms.

WVhat is claimed'is:

1. A collapsible tire building form, comprising a central supporting 'plate, an outer radial registeringsurface thereon, an annular wedge ring on said radial registering surface, a plurality of separable sections, and means for drawing the sections against the Wedge ring and register and clamping them in such position.

2. A sectional core for the purpose set forth, comprising a central core plate adapted to be received over the shaft of a tire machine, a registering surface on the outer periphery thereof and an outstanding flange, a plurality of core sections, the-inner portion thereof being adapted to seat upon the registering surface against the flange, and

-clamps-'tosecure the core sections in position, the clamps being provided with wedgi'ngsuifa'ces adapted to draw the sections to- Wardthe axisof .thecore as they are tightened.

' 3. A sectional core for the purpose set forth, comprising-a central core; plate adapted to be received over the shaft'of a tire-machine, a registering surface on theouter periphery thereof and an -outstanding*flange, a plurality of'core sections, the innerportion thereof being adapted to seat upon the registering surface against theflangeyand clamps to secure the core sections in position, the clamps andthe flange-beingprovided with wedging surfaces'adapted to draw the sections toward the axis'of the core as they'a-re tightened. I

4;. A core comprising a central-supporting plate, a sectional core body separable therefrom, theplatehaving an outer'core register, and means movable parallel with the axis of the core body to drawthe section radially inwardly and against the register.

5 A collapsible tire building core, comprising a central circular supporting plate, having an outer surface which is adapted to serveas-aregister,-anda plurality of'core sect-ions'locatcd around the plate, and wedging'means to secure-the sections imposition. 6. A'coll-ap'sible tlre building core, com- .prising a central chuck having 'an =outer conical surface thereon, an upstanding undercut flange at one; side thereof, asplurality of core sections each having a tongue adapted to seat upon the curved surface, each tongue being dovetailedin cross section, a plurality of clamps attached'to the core plate, each clamp having a wedge shaped outer 'endto engageone sideof'the dovel3t1llPQItIOIROftlI'Z-BCOIG sections,"- the opposite side belng located beneath the 1111- dercut flange and meansto guide the clamps for movement radially of the chuck.

8. A collapsible tire building core comprising a plate which constitutes a central supporting chuck member, a plurality of core sections encircling the chuck member, and releasable Wedge clamps on the chuck member adapted to hold the core sections.

FRANK L. JOHNSON. 

